Fan



April 1963 R. F. SCHWEGLER 3,085,632

FAN

Filed Dec. 8, 1959 3 Sheets-Sheet l INVENTOR For f Jc/nA E LE/Q ATTORNEYS April 16, 1963 R. F. SCHWEGLER FAN 3 Sheets-Sheet 2 Filed Dec. 8, 1959 INVENTOR Kay F JC/Vh/EG'AEX BY FM; @274:

ATTORNEYS April 16, 1963 R. F. SCHWEGLER FAN 3 Sheets-Sheet 3 Filed Dec. 8, 1959 INVENTOR for F JC/YWZ'GLER ATTORNEYS United States The present invention relates to fluid impelling devices, and more particularly to axial flow fans of multipart construction in which the parts may be readily and easily fabricated and assembled, and to a method of making the same.

An object of this invention is to provide an axial flow fan which is rigid and rugged in its construction and in which the blades are mounted upon, and removably se cured to, a centrally disposed blade supporting element such that the blades are in planes angularly disposed in respect to the plane of rotation of said supporting element.

Another object of this invention is to provide such a fan in which a supporting element is integrally attached to the root of the blades at right angles thereto and adapted to be removably bolted to a flanged periphery of a central disk in a manner to provide a smooth exterior of the flanged periphery.

Another object of this invention is to employ a central blade supporting disk having peripherally arranged flaps separated by curvilinear spaces such that when all of the flaps are bent at right angles to the disk, they form a circumferential flange having slots that conform to the curvilinear pitch of the blade.

Another object of the invention is to provide such an axial flow fan in which an integral blade supporting portion lies interiorly of, and between the disk flange and a reinforcing band that is also located interiorly of the flange and is bolted thereto.

In one aspect of the invention, a flanged disk may be formed from a substantially circular disk of sheet metal having equally spaced, peripherally arranged flaps. The flaps may be formed by removing equally spaced, peripherally arranged portions, each defined by two curvilinear edges that join each other at equally spaced points about a circle having a radius less than that of the circular disk by an amount equal to the width of the flange to be formed about the disk. By bending the flaps in the same direction and at right angles to the disk, a flanged disk is produced having equally spaced, peripherally arranged, curvilinear open end slots.

In another aspect of the invention, the fan blades may include a root-to-tip portion following generally an air foil cross section and a supporting portion at right angles to, and integral with the root of the blades. This supporting portion may have a curve in the direction of the blade width that generally conforms to the curve of the periphery of the flange of the central disk. Accordingly, a blade may be inserted within each slot about the periphery of the flanged disk in such fashion that the integral blade support may lie interiorly of the flange with the result that a smooth, uninterrupted flange exterior is provided from which radiate the fan blades.

In still another aspect of the invention, flange reinforcing means may be provided and it may take the form of a hoop or band means of rigid construction that may be located interiorly of the flange of the blade supporting disk such that the right angular supporting portion of the blades lies between the reinforcing band means and the flange of the disk. A plurality of bolts may extend through each flap, each right angular blade support and the band means, so that the assembly provides a rigid axial flow fan in which each blade may be removed independently of each other and a smooth, uninterrupted,

' atent 2 cylindrical surface may be provided from which the blades extend radially.

In still another aspect of the invention, a flanged hub may be bolted or otherwise fastened to the walls of the flanged disk such that said hub extends through a central hole within said disk.

The above, other objects and novel features of the new and improved axial flow fan will become apparent from the following specification and accompanying drawings which are merely exemplary.

In the drawings:

FIG. 1 is an elevational view of an axial flow fan to which the principles of the invention have been applied;

FIG. 2 is a side view of the fan shown in FIG. 1;

FIG. 3 is a plan view of a blank from which the flanged disk for supporting the fan blades is made;

FIG. 4 is a perspective view of a blade of the fan shown in FIG. 1;

FIG. 5 is a sectional view taken substantially along line 5-5 of FIG. 4; and

FIG. 6 is a side view of the flanged disk, showing the method of assembling a fan blade thereto.

Referring to the drawings, and particularly to FIG. 1, the principles of the invention are shown as applied to an axial flow fan comprising a disk 10 having a flange 11 integral therewith. Referring to FIG. 3, the flanged disk 10 may be made from a substantially circular piece of sheet metal or the like having a central hole 12 therein, and a plurality of holes 13 surrounding the hole 12 for a purpose to be; described later. Flaps 14 may be formed about the periphery of the piece of sheet metal by providing equally spaced recesses 15 about the circular piece of sheet metal. The recesses may comprise two similar curvilinear edges 16 and :17 that substantially intersect each other at a point on a circle of a diameter less than the diameter of the circular piece of sheet metal by an amount equal to the desired width of the flange to be formed. The edges 16 and 17 diverge outwardly from their intersecting point and terminate at points a substantial distance apart at the periphery of the circular piece of sheet metal. These recesses 15 may be cut from the piece of sheet metal, or may be blanked out with a die in a known manner.

By bending all of the flaps 14 in the same direction at right angles to the main body of the piece of sheet metal, a flange is formed about the disk 10' having equally spaced curvilinear slots 15 about the periphery of the flange 11 (-FIG. 6) which slots have a constant thickness.

Referring to FIGS. 4 and 5, blades 18 may comprise supporting plates 19 having a convex contour, looking from the tip of a blade toward its root, which convexity may have a radius equal to that of the flange 11. The blade 18 may have an air foil cross section of a design best suited for the desired characteristics of the fan. The curvature of the slots 15 (FIG. 6) may be identical with the curvature of the blades 1S so that in assembling the blades 18 to the flange 11, the blades can slide into the slots 15 with the plates 19 thereof located inwardly of the flange 11 and adapted to fit tightly against the inner periphery of the flange 11, with the outer convex surface of the plates mating with the inner concave surface of the flange 11.

Referring to FIG. 1, a band 20 may be provided for strengthening the assembly, and in the embodiment disclosed, it may comprise two sections 2.1 and 22. The width of the band 20 may be equal to the width of the flange 11, and each section 2.1 and 22 may have a deflected end portion 23 that overlaps the one end of the other section to complete a circular shape.

Referring to FIGS. 1, 4, 5 and 6, aligned holes 24 may extend through the flaps 14, the plates 19 and the 3 band sections 21 and 22. The holes 24 in the flaps 14 may be countersunk in order that the heads of bolts 25 (FIGS. 1 and 2) will be flush with the outer periphery of the flange 11. Nuts 26 may be screwed onto the bolts 25 so as to belocated on the inner peripheral surfaces of the band sections 1 and 22.

Referring again to FIG. 1, a hub portion 27 may extend through the hole 12 (FIG. 3) and may include a flange 28 having holes 29 therein that align with the holes 13 surrounding the hole 12 in the piece of sheet metal from which the flanged disk 10 is made. Bolts may pass through the holes 29 and 13 for rigidly fastening the hub 27 to the flanged disk 10. A keyway 30 may be provided Within the hub 27 for securing the assembled fan to a drive shaft.

Although the various features of the new and improved axial flow fan have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that numerous changes may be made in such details and certain features may be used without others without departing from the principles of the invention.

What is claimed is:

1. In an axial flow fan, a flanged disk; a plurality of open end slots at equally spaced intervals about the periphery of the flange of said disk; fan blades including supporting plates integrally connected to said blades at the roots thereof, said plates having a curvature corresponding to the peripheral curvature of said flange, the configuration of said slots corresponding to the transverse configuration of said blades whereby said blades may fit within said slots and said blade supporting plates may fit against the inner periphery of said flange; reinforcing hand means Within said flange and adapted to bear against the exposed surfaces of said blade supporting plates; and fastening means extending through said flange, blade supporting plates and band means for locking the assembly together.

2. In an axial flow fan, a flanged disk; a plurality of open end slots at equally spaced intervals about the periphery of the flange of said disk; fan blades including supporting plates integrally connected to said blades at the roots thereof, said plates having a curvature corresponding to the peripheral curvature of said flange, the configuration of said slots corresponding to the transverse configuration of said blades whereby said blades may fit within said slots and said blade supporting plates may fit against the inner periphery of said flange; overlapping rnulti-section band means within said flange and adapted to bear against the exposed surfaces of said blade supporting plates; and fastening means extending through said flange, blade supporting plates and band sections for locking the assembly together.

3. In an axial flow fan having blades with a transverse curvilinear section, a flanged disk having curved open end slots equally spaced about the periphery of the flange, the curvature of said slots corresponding to the curvature of the transverse section of said blades; supporting plates integral with and extending at right angles from the root of said blades, said plates having a curvature corresponding to the peripheral curvature of said flange whereby said blades may fit within said slots and said plates may fit against the inner periphery of said flange; and means for removably attaching said plates to said flange.

4. In an axial flow fan having blades with a transverse curvilinear section, a flanged disk having curved open end slots equally spaced about the periphery of the flange, the curvature of said slots corresponding to the curvature of the transverse section of said blades; supporting plates integral with and extending at right angles from the root of said blades, said plates having a curvature corresponding to the peripheral curvature of said flange whereby said blades may fit within said slots and said plates may fit against the inner periphery of said flange; reinforcing band means within said flange and adapted to bear against the exposed surfaces of said blade supporting plates; and fastening means extending through said flange, plates and band means for locking the assembly together.

5. In an axial flow fan, a flanged disk; a plurality of open end slots at spaced intervals about the periphery of the flange of said disk; fan blades each of uniform thickness for sliding within and lengthwise of a corresponding one of said slots upon assembly and disassembly of said blades, a supporting plate integrally connected to each of said blades at the root thereof, said plates each having an outer surface corresponding to an inner surface portion of said flange, the transverse configuration of each blade corresponding to the configuration of its slot, and means for removably fixing said plates to said flange, whereby said blades in a secured position within their slots form a rigid fan construction.

6. In an axial flow fan, a flanged disk; a plurality of curved open end slots at spaced intervals about the periphery of the flange of said disk; fan blades each of uniform thickness for sliding Within and lengthwise of a corresponding one of said slots upon assembly and disassembly of said blades, a supporting plate integrally connected to each of said blades at the root thereof, said plates each having an outer surface corresponding to an inner surface portion of said flange, the transverse configuration of each blade corresponding to the configuration of its slot, and means for removably fixing said plates to said flange, whereby said blades in a secured position Within their slots form a rigid fan construction.

References Cited in the file of this patent UNITED STATES PATENTS 484,511 Adams Oct. 18, 1892 828,867 Stoltenberg Aug. 14, 1906 974,496 Kemble Nov. 1, 1910 1,377,827 Garela May 10, '1921 1,773,349 Bothezat Aug. 19, 1930 2,022,417 Gilbert et al. Nov. 26, 1935 2,095,223 Samuels Oct. 5, 1937 2,234,319 Preston Mar. 11, 1941 2,302,437 Frisbie Nov. 17, 1942 2,362,868 Upson Nov. 14, 1944 2,411,143 Alizier Nov. 19, 1946 2,457,325 Sidell Dec. 28, 1948 2,496,179 Schwarz Jan. 31, 1950 2,649,243 Stalker Aug. 18, 1953 2,731,193 Lall et a1 Ian. 17, 1956 

1. IN AN AXIAL FLOW FAN, A FLANGED DISK; A PLURALITY OF OPEN END SLOTS AT EQUALLY SPACED INTERVALS ABOUT THE PERIPHERY OF THE FLANGE OF SAID DISK; FAN BLADES INCLUDING SUPPORTING PLATES INTERGRALLY CONNECTED TO SAID BLADES AT THE ROOTS THEREOF, SAID PLATES HAVING A CURVATURE CORRESPONDING TO THE PERIPHERAL CURVATURE OF SAID FLANGE, THE CONFIGURATION OF SAID SLOTS CORRESPONDING TO THE TRANSVERSE CONFIGURATION OF SAID BLADES WHEREBY SAID BLADES MAY FIT WITHIN SAID SLOTS AND SAID BLADE SUPPORTING PLATES MAY FIT AGAINST THE INNER PERIPHERY OF SAID FLANGE; REINFORCING BAND MEANS WITHIN SAID FLANGE AND ADAPTED TO BEAR AGAINST THE EXPOSED SURFACES OF SAID BLADE SUPPORTING PLATES; AND FASTENING MEANS EXTENDING THROUGH SAID FLANGE, BLADE SUPPORTING PLATES AND BAND MEANS FOR LOCKING THE ASSEMBLY TOGETHER. 